No males needed: All-female salamanders regrow tails 36 percent faster

Speedy regeneration could aid survival

Date:May 2, 2016

Source:Ohio State University

The lady salamander that shuns male companionship may reap important benefits.

For instance, when a predator snaps off her tail.

New research from The Ohio State University compared an all-female population of mole salamanders to a related heterosexual species and found they grew their tails back 36 percent faster. The unisexual salamanders (part of theAmbystoma genus) contain DNA of up to five species and reproduce primarily by cloning themselves.

Salamanders' tails play a critical role in predator avoidance. As larvae, tails help them swim away. Once the animals are land-dwellers, the tails act as a distraction.

After accounting for weight and size differences -- the all-female salamanders are larger and have more tail to grow back -- the team concluded that the unisexual animals regenerated tail tissue at 1.5 times the rate of their heterosexual counterparts.

"I don't think we expected it to happen so fast," said Robert Denton, co-author of the study and a graduate student in Ohio State's Department of Evolution, Ecology and Organismal Biology.

The study appears in the Journal of Zoology.

Populations of unisexual mole salamanders have survived millions of years through cloning. Because they aren't mating with males (though they do mix things up by "borrowing" sperm left behind on leaves and twigs), their DNA stays relatively static.

And that might lead a salamander scientist to suspect the species would fizzle out. (Passing harmful genetic mutations to generation after generation could be bad.)

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